Beverage containing tea polymerized polyphenol and rebd and/or rebm

ABSTRACT

Tea polymerized polyphenol-containing beverages having reduced bitterness and astringency of tea polymerized polyphenols while maintaining tea-like preferable flavors, methods of production thereof, and the like are provided. The content of tea polymerized polyphenols in a beverage is adjusted to within a certain range, the total content of RebM and RebD in the beverage is adjusted to within a certain range, and the weight ratio of the total content of RebD and RebM to the content of the tea polymerized polyphenols is adjusted to within a certain range.

TECHNICAL FIELD

Embodiments of the present invention relate to a beverage containing teapolymerized polyphenol and RebD and/or RebM.

BACKGROUND ART

Physiological effects of polyphenols have recently attracted attentiondue to the increase in health consciousness and the demand forpolyphenol-rich beverages has increased too. For example, teapolymerized polyphenols, a type of polyphenols, are known to have alipase inhibition effect, as described in Patent Literature 1, and thereare needs for beverages containing tea polymerized polyphenols.

Patent Literature 2 describes sweetener compositions and sweetenedcompositions containing one or more steviol glycosides includingRebaudioside X (RebX).

CITATION LIST Patent Literature

Patent Literature 1: WO 2005/077384

-   Patent Literature 2: National Publication of International Patent    Application No. 2015-502404

SUMMARY Technical Problem

Objects of embodiments of the present invention are to provide teapolymerized polyphenol-containing beverages having reduced bitternessand astringency of tea polymerized polyphenols while maintainingtea-like preferable flavors, methods of production thereof, and thelike.

Solution to Problem

Embodiments of the present invention provide beverages comprising a teapolymerized polyphenol at a content of 5 to 150 ppm and RebD and/or RebMat a total content of 20 to 300 ppm, wherein a weight ratio of a totalcontent (B) of RebD and RebM to a content (A) of the tea polymerizedpolyphenol (B/A) is 1.0 to 9.0, and others, but embodiments of thepresent invention are not limited thereto.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates the results of evaluation of masking effect of a teapolymerized polyphenol content (A) and a RebD content (B) in beveragesand a weight ratio (B/A) thereof on bitterness and astringencycharacteristic of tea polymerized polyphenols and the effect thereof onthe tea-like flavor.

FIG. 2 illustrates the results of evaluation of masking effect of a teapolymerized polyphenol content (A) and a RebM content (M) in beveragesand a weight ratio (M/A) thereof on bitterness and astringencycharacteristic of tea polymerized polyphenols and the effect thereof onthe tea-like flavor.

FIG. 3 illustrates the results of evaluation of masking effect of RebAon bitterness and astringency characteristic of tea polymerizedpolyphenols and the effect thereof on the tea-like flavor.

FIG. 4 is an example of HPLC charts obtained by measuring samplescontaining a tea polymerized polyphenol.

DESCRIPTION OF EMBODIMENTS

<Beverage>

Embodiments of the present invention are beverages comprising a teapolymerized polyphenol at a content within a certain range and RebDand/or RebM at a total content within a certain range, wherein theweight ratio of the total content of RebD and RebM to the content of thetea polymerized polyphenol is within a certain range.

Tea polymerized polyphenols (also referred to as tea polymerizedcatechins) are known to be a type of polyphenols and have acharacteristic bitter taste and astringency. As used herein, the bittertaste and astringency characteristic of tea polymerized polyphenols maybe described as the “bitterness and astringency”.

In embodiments of the invention, the content of the tea polymerizedpolyphenol is 5 to 150 ppm (0.0005 to 0.015% by weight), preferably 30to 140 ppm, more preferably 40 to 130 ppm, further more preferably 60 to125 ppm, and most preferably 85 to 120 ppm relative to the weight of thebeverage. Unless otherwise specified, “ppm”, as used herein, meansweight/weight (w/w) ppm.

The “tea polymerized polyphenol” as used herein refers to a componentthat has a structure in which plural non-polymerized, monomericcatechins ((+)-catechin, (−)-epicatechin, (+)-gallocatechin,(−)-epigallocatechin, (−)-catechin gallate, (−)-epicatechin gallate,(−)-gallocatechin gallate, (−)-epigallocatechin gallate (herein, theseare also described as the “non-polymeric catechin”)) are linked by atea-derived enzyme, an enzyme, light, pH change or the like and thatexhibits a peak at the same elution time (reference elution time: 25minutes) as theaflavin (a product of Kurita Research Center) whenanalyzed by HPLC in the following conditions.

-   -   Column: TSK-gel ODS-80TsQA (4.6 mmφ×150 mm, Tosoh Corporation);    -   Mobile phase:

A: water:acetonitrile:trifluoroacetic acid=900:100:0.5;

B: water:acetonitrile:trifluoroacetic acid=200:800:0.5

-   -   Flow rate: 1.0 ml/min    -   Column temperature: 40° C.    -   Gradient conditions:

0% Solution B from the start of analysis to 5 minutes later,

8% Solution B from 5 minutes to 11 minutes,

10% Solution B from 11 minutes to 21 minutes,

100% Solution B from 21 minutes to 22 minutes,

Maintaining 100% from 22 minutes to 30 minutes,

0% from 30 minutes to 31 minutes.

-   -   Detection: A280 nm (data collection time 30 minutes), quantified        in peak area.    -   Injection volume: 10 μL    -   Standard substance: Oolonghomobisflavan B (abbreviation: OHBF-B)

The amount of tea polymerized polyphenols is determined by using OHBF-Bas a standard substance and preparing a standard curve. OHBF-B used asthe standard substance may be, for example, one synthesized (preferablypurified to a purity of 98% or more) according to the method describedin Chem. Pharm. Bull 37 (12), 3255-3563 (1989) or the method describedin Japanese Patent Laid-Open No. 2005-336117 (Example 3), one isolatedfrom tea leaves, or the like.

Under the analysis conditions described above, a peak of a teapolymerized polyphenol may overlap with a peak of another component.Examples of beverages containing such another component includebeverages containing fruit juice, beverages containing a plant extract,and the like. In such a case, the analysis conditions described aboveare not suitable for quantification of the tea polymerized polyphenol,although they are suitable for identification thereof. In such a case, apeak that appears at approximately 14 minutes is used for thequantification. The value obtained by multiplying the peak area of thepeak at approximately 14 minutes by 10 and the peak area of the peak atapproximately 25 minutes are compared. If the former value is lower,then the former value is used for quantification of the tea polymerizedpolyphenol. An example of HPLC charts in which these peaks are seen isshown in FIG. 4.

In embodiments of the present invention, the origin of the teapolymerized polyphenol is not particularly limited. For example, it maybe one derived from a natural product, one obtained on the market, orone synthesized by an organic chemical method, but it is preferably atea polymerized polyphenol derived from a natural product in view of arecent increase in nature orientation. Examples of the natural productsinclude, but are not limited to, tea (green tea, white tea, black tea,oolong tea, mate, and the like). In embodiments of the presentinvention, the tea polymerized polyphenol is preferably derived from teaand more preferably derived from tea leaves of half fermented tea orfermented tea containing a plenty of the tea polymerized polyphenol, inparticular derived from oolong tea leaves. Moreover, the tea polymerizedpolyphenol may be a mixture of tea polymerized polyphenols of differentorigins.

The tea polymerized polyphenol used in embodiments of the presentinvention is exemplified by, besides the tea polymerized polyphenolcalled with common names such as thearubigin specifically, teapolymerized polyphenols such as an epigallocatechin gallate dimerrepresented by the formula (1):

an epigallocatechin gallate trimer represented by the formula (2):

an epigallocatechin dimer represented by the formula (3):

wherein R1 and R2 are each independently H or a galloyl group;

an epigallocatechin trimer represented by the formula (4):

wherein R3, R4 and R5 are each independently H or a galloyl group;

oolongtheanin-3′-O-gallate represented by the formula (5):

and may be selected from the group consisting of these compounds.

In embodiments of the invention, the tea polymerized polyphenol can beobtained as a plant extract containing the tea polymerized polyphenol.The plant extract is preferably derived from Camellia sinensis. It isobtained, for example, by a solvent extraction from tea leaves ofCamellia sinensis. Tea leaves used as a raw material may be one or moreof green tea, which is unfermented tea, oolong tea, which is halffermented tea, and black tea, which is fermented tea, but, among others,tea leaves of half fermented tea or fermented tea containing a plenty ofthe tea polymerized polyphenol, in particular tea leaves of oolong teaare preferably used. Extraction solvents that may be used include wateror hot water, methanol, ethanol, isopropanol, ethyl acetate, and thelike and it may be extracted with one or a mixture of 2 or more ofthese. A preferred extraction solvent is hot water, to which sodiumbicarbonate may be added as needed. A solvent extract of these tealeaves may be used as it is without purification, but a concentrated orpurified extract, that is, a solvent extract of tea leaves from whichcomponents other than the tea polymerized polyphenol are selectivelyremoved to increase the content of the tea polymerized polyphenol ispreferably used. Since non-polymeric catechin generally has bitternessand astringency, it is particularly preferable that non-polymericcatechin is selectively removed. Examples of extracts thus obtainedinclude extracts containing a tea polymerized polyphenol at aconcentration which is 4 times or more high as the concentration ofnon-polymeric catechin described in WO2005/077384 and the like.

Moreover, tea leaves may be subjected to extraction as it is orsubjected to extraction after treating the tea leaves containing the teapolymerized polyphenol and the non-polymeric catechin with an enzymesuch as polyphenol oxidase or the like to further increase the degree ofpolymerization of the tea polymerized polyphenol or an extract may besubjected to such an enzymatic treatment. The higher the degree ofpolymerization is and the higher the ratio of the tea polymerizedpolyphenol to the non-polymeric catechin is, the less unpleasantbitterness and astringency is present and the more preferable the flavorbecomes.

In beverages of embodiments of the present invention, low contents ofnon-polymeric catechin are preferable. The weight ratio (tea polymerizedpolyphenol content/non-polymeric catechin content) of the teapolymerized polyphenol content to the non-polymeric catechin content inthe beverages is preferably 1 or more, more preferably 1.2 or more, andmore preferably 1.4 or more. To produce such beverages, the techniquedescribed in WO2005/077384 or the like may be used.

Rebaudiosides (hereinafter, abbreviated as “Rebs”) are known as sweetcomponents contained in stevia extracts. The stevia extracts areextracts obtained by extraction and/or purification from stevia dryleaves. Stevia is a perennial plant in Asteraceae that is native toParaguay in South America and its scientific name is Stevia RebaudianaBertoni. Because stevia contains components having about 300 times ormore the sweetness of sugar, it is grown for extraction and use of thesesweet components as a natural sweetener. Known Rebs include RebA, RebB,RebC, RebD, and RebE. Furthermore, the presence of various glycosidessuch as RebM described in National Publication of International PatentApplication No. 2012-504552 has been recently reported. Embodiments ofthe present invention involve particularly RebM and RebD as steviaextracts. RebD and RebM may be obtained on the market or synthesized byan organic chemical method. Moreover, RebD and RebM may be separated andpurified from a stevia extract as a starting raw material. For example,RebD can be purified according to the method described in U.S. Pat. No.8,414,949 and RebM can be purified according to the method described inFoods 2014, 3 (1), 162-175; doi: 10.3390/foods3010162. Methods foranalyzing RebD and RebM are not particularly limited and known methodsmay be used, but, for example, they can be analyzed with a highperformance liquid chromatograph (HPLC) under the conditions describedin National Publication of International Patent Application No.2012-504552. RebD and RebM are analyzed herein by the method, unlessotherwise described.

Beverages of embodiments of the present invention may contain one orboth of RebD and RebM and the total content of RebD and RebM relative tothe weight of the beverage is 20 to 300 ppm (0.002 to 0.03% by weight),preferably 30 to 290 ppm, more preferably 40 to 280 ppm, and furthermore preferably 60 to 250 ppm.

In embodiments of the present invention, bitterness and astringencycharacteristic of tea polymerized polyphenols can be reduced whilemaintaining the tea-like preferable flavor in the tea polymerizedpolyphenol-containing beverages by adjusting the content of the teapolymerized polyphenol and the total content of RebD and RebM within theranges described above. In embodiments of the present invention, tastesand aromas of the tea polymerized polyphenol itself may remain as longas bitterness and astringency characteristic of tea polymerizedpolyphenols can be reduced. The “tea-like preferable flavor” as usedherein refers to having a refreshing aroma and a rich tastecharacteristic of tea.

Further, in the embodiments, the weight ratio of a total content (B) ofRebD and RebM to a content (A) of the tea polymerized polyphenol ([totalcontent of RebD and RebM])/[content of tea polymerized polyphenol](B/A)) is 1.0 to 9.0, preferably 1.4 to 7.0, more preferably 1.6 to 6.0,and further preferably 2.0 to 5.0. If A and B meet the conditions, thenbitterness and astringency characteristic of tea polymerized polyphenolscan be effectively reduced while maintaining the tea-like preferableflavor in the tea polymerized polyphenol-containing beverages.

Moreover, in beverages of embodiments of the present invention, thecontent of RebD relative to the weight of the beverage is 20 to 300 ppm(0.002 to 0.03% by weight), preferably 30 to 290 ppm, more preferably 40to 280 ppm, and further more preferably 60 to 250 ppm. Furthermore, inembodiments of the invention, the weight ratio of the content of RebD tothe content of the tea polymerized polyphenol ([content ofRebD]/[content of tea polymerized polyphenol]) is 1.0 to 9.0, preferably1.4 to 7.0, more preferably 1.6 to 6.0, and further more preferably 2.0to 5.0.

In beverages of an embodiment of the present invention, the content ofRebM relative to the weight of the beverage is 20 to 300 ppm (0.002 to0.03% by weight), preferably 30 to 290 ppm, more preferably 40 to 280ppm, and further more preferably 60 to 250 ppm. Furthermore, inbeverages of an embodiment of the invention, the weight ratio of thecontent of RebM to the content of the tea polymerized polyphenol([content of RebM]/[content of tea polymerized polyphenol]) is 1.0 to9.0, preferably 1.4 to 7.0, more preferably 1.6 to 6.0, and further morepreferably 2.0 to 5.0.

Beverages of embodiments of the present invention may contain, asneeded, additives usually contained in beverages, for example,antioxidants, emulsifiers, nutrient supplements (vitamins, calcium,minerals, amino acids), flavors, pigments, preservatives, flavoringagents, extracts, pH regulators, quality stabilizer, fruit juice, fruitjuice puree, and the like. These additives may be blended singly in thebeverages or a plurality of these components may be blended incombination in the beverages.

Embodiments of the present invention are not particularly limited, butexamples include refreshing beverages, non-alcoholic beverages,alcoholic beverages, and the like. The beverages may be beveragescontaining no carbonic acid gas or may be beverages containing carbonicacid gas. Examples of the beverages containing no carbonic acid gasinclude, but are not limited to, tea beverages such as green tea, oolongtea, black tea, barley tea, mate, and the like, coffee, fruit juicebeverages, milk beverages, sports drinks, and the like. Examples of thebeverages containing carbonic acid gas include, but are not limited to,cola, diet cola, ginger ale, soda pop, and carbonated water providedwith a fruit juice flavor. In particular, from a point of view tomaintain the tea-like preferable flavor, embodiments of the presentinvention are preferably tea beverages such as green tea, oolong tea,black tea, barley tea, mate, and the like.

Beverages of embodiments of the present invention may be provided incontainers, as needed. The form of the containers is not limited at alland the beverages may be filled into containers such as bottles, cans,barrels, or PET bottles and provided as beverages in containers.Moreover, the method of filling the beverages into containers is notparticularly limited.

<Method of Producing Beverage and Method of Reducing Bitterness andAstringency of Tea Polymerized Polyphenols while Maintaining Tea-LikePreferable Flavor in Beverage>

According to another aspect of embodiments of the present invention,methods of producing beverages are provided. A method of productionaccording to an embodiment of the present invention comprises the stepof blending a tea polymerized polyphenol and RebD and/or RebM such thatthe content of the tea polymerized polyphenol becomes 5 to 150 ppm, thetotal content of RebD and RebM becomes 20 to 300 ppm in beverages, andthe weight ratio of a total content (B) of RebD and RebM to a content(A) of the tea polymerized polyphenol (B/A) is 1.0 to 9.0. The method ofblending the tea polymerized polyphenol is not particularly limited and,for example, the tea polymerized polyphenol itself may be blended or araw material containing the tea polymerized polyphenol may be blended.Moreover, the method of blending RebD and/or RebM is not particularlylimited as well and RebD and/or RebM itself may be blended or a rawmaterial containing RebD and/or RebM may be blended. Preferable teapolymerized polyphenols and preferable content ranges thereof,preferable total content ranges of RebD and RebM, and preferable rangesof the weight ratio (B/A) are as described above as for beverages.

The method of production according to the embodiment of the presentinvention may comprise the step of blending an additive that is usuallyblended into beverages and/or the step of filling a beverage into acontainer. Types of the additive and the container are as describedabove as for beverages and filling of the container may be done by usinga known method.

The method of production according to the embodiment of the presentinvention can reduce bitterness and astringency characteristic of teapolymerized polyphenols while maintaining a tea-like preferable flavorin tea polymerized polyphenol-containing beverages. Accordingly, themethod of production is, in another aspect, a method for reducingbitterness and astringency of tea polymerized polyphenols whilemaintaining a tea-like preferable flavor in a beverage.

Hereinafter, embodiments of the present invention are describedreferring to specific examples, but the present invention is not limitedthereto.

The effect of the tea polymerized polyphenol content (A), RebD and/orRebM content (B) in beverages, and the weight ratio (B/A) thereof on thetea-like preferable flavor and the bitterness and astringency of teapolymerized polyphenols can be determined as follows. The teapolymerized polyphenol and RebD were blended and sample beverages(Example 1 to 10, Comparative Examples 1 to 8) were prepared. The teapolymerized polyphenol content and the RebD content in the samples weremeasured. Furthermore, based on the tea polymerized polyphenol content(A) and the RebD content (B) measured, the RebD content/tea polymerizedpolyphenol content weight ratio (B/A) was calculated. Subsequently, asensuality evaluation test for “masking effect of bitterness andastringency” and “tea-like flavor” by expert panels was conducted bytasting of sample beverages according to the following standards. 5expert panels conducted the evaluation and graded the samples 1 to 5points at 0.1 points intervals for the evaluation criteria. × was markedwhen the average of points by the 5 panels is less than 3; ◯ was markedwhen the average is equal to or more than 3 and less than 4.5: and ⊚ wasmarked when the average is equal to or more than 4.5.

<Criteria for Sensuality Evaluation>

-   ⊚: very preferable-   ◯: preferable-   ×: unfavorable

The tea polymerized polyphenol content and the RebD content in samplebeverages and the results of the sensuality evaluation are illustratedin FIG. 1. It was shown, as described in FIG. 1, that bitterness andastringency of the tea polymerized polyphenol can be masked whilemaintaining the tea-like flavor by adjusting the tea polymerizedpolyphenol content and the RebD content within the range according tothe present invention and adjusting the weight ratio of RebD content/teapolymerized polyphenol content within the range according to the presentinvention.

The tea polymerized polyphenol additionally blended in the descriptionabove was prepared as follows.

600 kg of oolong tea leaves were subjected to an extraction treatmentwith 7800 kg of a sodium bicarbonate solution obtained by adding 0.15%by weight of sodium bicarbonate into hot water (95° C.) to obtainapproximately 7000 kg of an oolong tea extract. Non-polymeric catechinand caffeine were removed by passing the extract through 400 kg ofgranular active carbon (GW-H32/60 manufactured by Kuraray Co., Ltd.)while maintaining the temperature of this extract within 60 to 65° C.This passage liquid (liquid after the active carbon treatment) wasconcentrated under reduced pressure to obtain approximately 900 kg of ahigh content tea polymerized polyphenol extract (concentrate of oolongtea extract, extract) with Brix 11. The tea polymerized polyphenolconcentration in extract A obtained was measured by HPLC under theconditions described above. As a result, the concentration of the teapolymerized polyphenol was 12,000 ppm.

Moreover, sample beverages (Examples 11 to 14, Comparative Examples 9 to14) were prepared in the same way as described above except that RebMwas used instead of RebD. It was also demonstrated that if the teapolymerized polyphenol content, the RebM content, and weight ratio (M/A)of rebM content/tea polymerized polyphenol content were adjusted withinthe range according to the present invention, then bitterness andastringency of the tea polymerized polyphenol can be masked whilemaintaining the tea-like flavor, similar to the case with RebD (FIG. 2).

Furthermore, the difference between the effects of different Rebs on thetea-like preferable flavor and bitterness and astringency of teapolymerized polyphenols in tea polymerized polyphenol-containingbeverages was examined as follows. First, sample beverages ofComparative Examples 15 and 16 were prepared in the same way asdescribed above except that RebA was used instead of RebD and RebM. Thetea polymerized polyphenol content and the RebA content in each beveragewere measured and weight ratio (C/A) of RebA content/tea polymerizedpolyphenol content was calculated (FIG. 3). A sensuality evaluation testwas conducted according to the method described above. The results areshown in FIG. 3. It was revealed, as described in FIG. 3, that theeffect that allows masking bitterness and astringency of tea polymerizedpolyphenols while maintaining the tea-like flavor observed with. RebDand RebM was hardly observed with RebA.

Stating for clarification, the numerical range expressed herein with alower limit value to an upper limit value, namely, “lower limit value toupper limit value” includes the lower limit value and the upper limitlevel value. For example, the range expressed as “1 to 2” includes 1 and2.

1. A beverage comprising a tea polymerized polyphenol at a content of 5to 150 ppm and RebD and/or RebM at a total content of 20 to 300 ppm,wherein a weight ratio of a total content (B) of RebD and RebM to acontent (A) of the tea polymerized polyphenol is 1.0 to 9.0, whereinsaid weight ratio refers to as B/A.
 2. The beverage according to claim1, wherein the weight ratio of the total content (B) of RebD and RebM tothe content (A) of the tea polymerized polyphenol is 2.0 to 5.0, whereinsaid weight ratio refers to as B/A.
 3. The beverage according to claim1, further comprising a non-polymeric catechin, wherein a weight ratioof a content of the tea polymerized polyphenol to the content of thenon-polymeric catechin (tea polymerized polyphenol content/non-polymericcatechin content) is 1 or more.
 4. The beverage according to claim 2,further comprising a non-polymeric catechin, wherein a weight ratio of acontent of the tea polymerized polyphenol to the content of thenon-polymeric catechin (tea polymerized polyphenol content/non-polymericcatechin content) is 1 or more.